Module KillUselessMoves

Require Import Coqlib Maps Errors Integers Floats Lattice Kildall.
Require Import AST Linking.
Require Import Memory Registers Op RTL.
Require List.

Definition transf_ros (ros: reg + ident) : reg + ident := ros.

Definition transf_instr (pc: node) (instr: instruction) :=
  match instr with
  | Iop op args res s =>
    if (eq_operation op Omove) && (List.list_eq_dec peq args (res :: nil))
    then Inop s
    else instr
  | Iassert _ _ s => Inop s
  | _ => instr
  end.

Definition transf_function (f: function) : function :=
  {| fn_sig := f.(fn_sig);
     fn_params := f.(fn_params);
     fn_stacksize := f.(fn_stacksize);
     fn_code := PTree.map transf_instr f.(fn_code);
     fn_entrypoint := f.(fn_entrypoint) |}.

Definition transf_fundef (fd: fundef) : fundef :=
  AST.transf_fundef transf_function fd.

Definition transf_program (p: program) : program :=
  transform_program transf_fundef p.